Scientific issues in the restoration of salmonid fishes in the Columbia River

The Columbia River once was one of the most productive river basins for ana dromous salmonids on the West Coast of North America; however, its current runs total less than 10% of historic levels. The Independent Scientific Gro up (ISG) of the Northwest Power Planning Council reviewed regional salmon m anagement actions described in the Columbia River Basin Fish and Wildlife P rogram and concluded that the current program is unlikely to recover declin ing salmon and steelhead stocks. Adoption of a salmon life history ecosyste m concept as a sliding foundation is needed to recover depressed stocks. In creasing natural ecosystem processes and functions should rebuild salmon po pulations to more abundant, productive, and stable levels. Elements of a sa lmon recovery program that increase these normative conditions include rest oration of habitat for all life history stages (including migrations), redu ction of mortality sources (including harvesters), planning of hydropower m itigation measures in the context of the normative river concept, and empir ical evaluation of mitigation for effectiveness in reaching fish restoratio n objectives. Salmon need to be managed for population and life history div ersity not just for harvest. Reserves that protect remaining core populatio ns and intact habitats are needed to foster a step-by-step rebuilding of sa lmon abundance and productivity.